Enforcement of most malum prohibitum law is a really ****ty thing to do.To each their own, but I prefer the ungoverned route. No sense in destroying history over an arbitrary law that I didn't vote for in the first place. I wouldn't parade the rifle around, but I wouldn't be scared to own it.
Especially in a case like this where someone filed off a serial number. If it was proven to be stolen, then prosecute away.
(I am NOT saying the OP or anyone related to him stole this carbine.)